iXblue launches quantum sensor for precise underground mapping

12 May 2022

System is based around “agile” laser system; can detect a 40cm diameter pipe buried 2m deep.

High-tech firm iXblue has announced a scientific and technological breakthrough with the development of what the Saint-Germain-en-Laye, France-based firm is calling “the first industrial compact and transportable Differential Quantum Gravimeter in the world”.

With its high sensitivity and unreported stability, iXblue’s compact gravity gradiometer is said to offer new perspectives for near-surface geophysics, civil engineering, and gravity-aided navigation.

The industrial prototype of DQG developed (and validated) by iXblue Quantum Sensors division can measure simultaneously the absolute values of both gravitational acceleration g, and its vertical gradient Γ_zz.

On the one hand, the gradient is more sensitive to mass anomalies at close vicinity of the sensor, while its immunity to vibrations makes it more sensitive to smaller objects. And on the other, gravity is more sensitive to bigger objects, further away. The DQG offers the best of both worlds and the fusion of the two datasets promises to remove the ambiguity between the determination of the mass of the gravity anomaly and its location.

Simultaneous measurement

Camille Janvier, a quantum physicist at iXblue, explained, “Our prototype is the first industrial solution to offer this simultaneous measurement. Its resolution being better than 1 E* makes it capable of detecting very small anomalies while being non-invasive and not requiring a precise knowledge of the terrain’s topography.”

“Our DQG can detect a 40cm diameter pipe almost 2m under the ground.” He added.

The gravitational acceleration g measured by iXblue’s DQG has the same performance as the firm’s commercial Absolute Quantum Gravimeter, and its sensitivity to vertical gravity gradient Γ_zz is currently limited by a purely quantum effect.

These performances were obtained thanks to iXblue’s experience in integrating complex systems for quantum technologies. In particular, the DQG features a compact and agile laser system that is similar to the commercial Intelligent Laser System series commercialized by iXblue. It allows a precise control of the laser amplitude, phase and absolute frequency with fast tunability.

Janvier added, “The compactness of the DQG and the field-tested technology on which it is based, open the way to the deployment of this new quantum sensor in real environments in the near future, to investigate both spatial and temporal variations of mass distributions in the field.”

The DQG is now commercially available. It is a groundbreaking solution for gravity measurements with applications in:

• Civil engineering and defense for the detection of underground cavities
• Improved capabilities in mining, and prospection
• Better accuracy for reservoir management in geothermy
• Improvement of infrastructure monitoring

The quality of iXblue’s DQG is the result of both the expertise of its teams on the physics behind this technology, and the very tight and fruitful partnership with the academic team from LNE-SYRTE lab (Observatoire de Paris/PSL/CNRS/Sorbonne Univ.) in Paris, France.

• For people interested to know more about this development, iXblue is hosting a webinar Quantum Gravity Gradiometer for Accurate Underground Mapping on May 19, 2022.